I'm in Perth. Our feed in tariff changed in July to 10c/kWh between 3pm and 9pm, and 2.5c/kWh at other times. Use tariff is 26.2c/kWh. I'm pretty sure our solar will pay itself back in under 5 years, but we have a 25 year warranty on the panels.
My parents are building outside of Adelaide and they've decided to go off grid (solar + battery + backup generator). Their expected payback period is (iirc) 8 years, with a 10 year warranty on the batteries and a 25 year warranty on the panels. They're expecting to have to run the generator once a year or so.
Dunno if your geographic size argument holds much water. Australia is about the same size as the continental US, but we always get lumped in as one entity. Canada appears to get the same treatment.
My parents are building outside of Adelaide and they've decided to go off grid (solar + battery + backup generator). Their expected payback period is (iirc) 8 years, with a 10 year warranty on the batteries and a 25 year warranty on the panels. They're expecting to have to run the generator once a year or so.