I think there are still govt incentives for solar but they have changed.

An average household with 2 adults and 2 kids would need a 3.0 kw system to cover all of their electricity usage.

The incentives cover a 1.0 or 1.5 kw system.

If you generate more electricity than you use you can feed it back to the grid and earn $, the amount depends where you live.

A colleague knowing all this, installed a 5kw system which means the excess power he sells back fully covers the cost of the repayments on his system, plus he gets no electricity bill.