I've just ordered ours here in Perth. Our feed in tariff is only 7c per unit here. Speaking of units... you're using 'KW' for 'kWh'. kW is a measure of power, ie the rate at which work is being done. kWh is a measure of work done, ie using a power of one kW for one hour, also called "a unit". Your panels have generated 8.6mWh of electricity.
Other annoying things about power here in WA (in addition to the measly 7c/unit FIT)
Maximum 5kW inverter (with max 6.65kW panels attached) for single phase
If you have three phase power you're allowed more capacity... but only as approved by Western Power, so they can avoid suburbs going too voltage-high. That's reasonable, although I would prefer to see a system that encourages all the solar you want and solves the over-voltage in a different way. The unreasonable part is that Synergy (the monopolistic power seller in Perth) will not pay you for any of you exported power if you have more than 5kW of inverter capacity. They'll just steal it. This was probably signed into law by a government that wants to maximise profits for the power selling utility before privatising it in a few years.
I went for an expensive system, with 25 years parts/labour/performance on panels because I detest the idea wasting time doing it all again in 10 years, also I don't like the idea of putting all those panels in to landfill. So I got 20.4% efficiency panels, which may help with roof space down the track if I decide to double or triple my capacity.
My payback is 3.4 years... in theory. Estimates by solar installers vary wildly, and the online solar calculator I used is clearly oversimplified.
Hopefully in 5 years or so it will be viable to add a battery and save the 'other half' of my power bill. My usage is high from too many computers and aquariums and ponds.
But today in pretty much every state it's a no-brainer to install solar, for most people it's a 20% to 40% yield on investment.
I could even install battery right now and still have a 7 year pay back... mainly due to my too-high usage. But it's not a good enough return to tempt me, especially when everyone thinks battery technology/scale will improve within 5 years or so.