My main motivation is that I don't want to be paying big bills when I'm not earning money down the track, plus the environmental reasons too.
We use about 5.5kWh a day on average BTW, so we're fairly low users.
Re economics I've found out the following:
I can keep the FIT as long as I use the same inverter.
I can overload the SB1700 inverter with 2.8kW of PV, some facing west and some north.
Total installed cost will be about $2,500 after rebates.
The system will generate 2MW more per year than the current system.
2MW with FIT is about $1,000 a year, so payback in 2.5 years.
I think it's better economically to change the system now whilst I can get the FIT since it reduces the payback time drastically.
3.12kW grid connect PV system (REC 260s, SMA 1700). Half N, half tilted west
Solahart thermosiphon solar hot water, 180L
14,000L rainwater tank
Greyflow grey water system
Located near Fremantle, WA