It's difficult / expensive to store electricity. If you have a large fluctuation in electricity use, you either need hydro to store, or you need surplus power generation on standby, which is expensive. So they try and predict peak use, and sometimes get it wrong.
I guess that's why solar would be good for Australia, as it provides power when you need it. Although the cells lose efficiency when they get too hot.
Plus Aust has other problems to deal with. Dust buildup can cause shorts.
Plus I think Australian electricians don't work live, whereas they tend to work live more in the UK. Or so I was told, but I'm not an electrician.