You would probably have to prove negligence was the cause of the outage to get compensation. As all of the electricity contracts I have seen always state that they don't guarantee a continuous supply. And the first question from the defence lawyer in any compensation court case will be "why didn't you have backup generators installed"
A reminder for account holders affected by the Vector Penrose power outage in October 2014. If you were an impacted electricity account holder on 5 October 2014, you can apply here for your compensation payment - $50 for residential customers and $200 for affected businesses.