On the other side of the Tasman they're pretty common due to summer storms. In Queensland having candles ready when we sat down for dinner was an almost daily occurrence some months, the PC and just about everything else would be turned off and unplugged by then. The best nights were when the power went early and we had an emergency Barbecue.

Over the years it got more reliable but I'm not sure if that was universal or just my specific area getting a lot more built up.