@jenchris,
As I said, "I'm sure that batteries will be part of the mix for energy stability / security". You're also 100% correct that load balancing strategies (off-peak hot water, etc) will also help enormously.
100 MW.hr of batteries would be a very useful piece of infrastructure - but it won't "fix" South Australia's energy problems. Let's just remind ourselves of what actually happened on 28 September (the state-wide blackout which precipitated all the recent talk about energy security):
. 445 MW of wind production was lost due to system issues during the storm event. Elon Musk's proposed battery could have picked up that load for about 13 minutes - but only if it was located so as to still be accessible by the customers. Note that the fundamental problem was faults in the transmission system (the "poles and wires"), not the wind turbines themselves. If the transmission system fails, it doesn't matter how much generating capacity you have, the power can't get to where its needed!
. The load was shifted onto the Heywood Interconnector, which shut down when its automatic overload protection system kicked in. This meant that there was now a loss of supply of 900 MW (or about 6 minutes of battery back-up).
[Ref:
https://www.aemo.com.au/-/media/File...ATE-REPORT.pdf ]
100 MW.hr of battery back-up may or may not have helped for the specific set of circumstances on 28 September (but only if it was appropriately located to deal with the transmission system faults), but it is simply not big enough to "fix" South Australia's energy problems.
Realistically, you are looking at multiple-gigawatt-hours of storage, at distributed locations across the state, to really provide the kind of security that people are envisaging. 100 MW.hr of battery back-up would just be the first small step in this process.
Don't get me wrong - I'm not arguing against pursuing this idea, just raising a note of caution that it could be a very expensive white elephant if it isn't planned and thought through properly. If nothing else, we mustn't let the politicians declare the problem to have been "fixed" if / when they sign a deal with Elon Musk (or whoever) to build a giant battery pack somewhere in suburban Adelaide.