Also, the last Mad Max was mostly filmed in Namibia. The older ones were filmed in Australia, notably Coober Pedy, which is north of Adelaide and not near the Nullarbor.
The originals were filmed just outside Broken Hill actually. There is a sign on the highway way to Mildura, and there is a big lot where you can see some of the props from Number 3 (notably the plane). I grew up in Mildura.
Also, the latest was filmed in Messum Crater in Namibia, I spent some time exploring there too - (bottom half of this post/pictures) http://theroadchoseme.com/riverbeds-and-craters
You're correct about the second being up Broken Hill way.
This won't happen because it would be politically difficult, and because the power companies would lose a lot of money as consumption fell through the floor. They don't want too much battery for a while because this would require them to move from a usage model to a majority fixed fee billing. To reduce public outrage the changeover needs to be slow.