here is some info Stevo
hope this helps
Our last bill with origin was approx $650
we moved to AGL when the input output meter was fitted and this quarters bill
was $1110.20 in credit.
AGL will send out your credit in a cheque.
As for paying tax?
So, is solar power income taxable?
As the ATO spokesperson said, and as has been reported on numerous industry web sites, the income derived from a small solar system installed on an owner-occupied residential dwelling is generally not taxable. I have to cover myself, though, and state that this is not tax advice and you need to obtain your own advice based on your unique situation from your accountant or tax agent.
It sounds like people installing large systems with the intention of making money will be required to pay tax on the income, though. This also means they’ll be able to claim depreciation on the asset and the costs of maintaining their system, just like any other income-producing asset. With rising electricity prices and falling solar panel prices, these systems can be a good investment.
One interesting aspect of the income from solar power systems is that it is counted as income for social security purposes (see section titled “Feed in tariff income and social security”).
I also found this: