Yeah I don't know how it all works and how much a system is capable of feeding back in, but it says you're eligible for the tarrif as long as you have a 5kw or less system, and don't use more than 100,000kWh per year, which I don't think any house would even go close to (just assuming)
My parents went ahead and got it without researching too much, so I'm trying to find out all I can now to see if it's worth it or not, and hope there's a cooling off period (it's not installed yet)