I’m moving house in a couple of weeks and will be a home owner for the first time in a while and because of this I’m planning on doing a lot of work on the new house. One of these projects is to get a rooftop photo-voltaic (PV) system installed and cut back on power costs and (hopefully) benefit by selling excess generated power back into the grid. The South Australian state government (I live in South Australia, a southern state of Australia) is offering a $0.44 per kW/h feed in tariff (FIT) for rooftop PV systems approved by 30 September 2011 and installed by the end of 2011. FIT payments are guaranteed until 2026 and power retailers may also offer up to an additional 8c / kWh giving a total of $0.52 / kWh for excess power generated by your rooftop PV system.

The real benefit of a rooftop PV system only really comes into play when the power it generates exceeds the power used. For example, if your system is generating 10 kW/h during the day but you are consuming 12 kWh the system only offsets the power you use. My last power bill was charged at almost exactly $0.25 kWh so a PV system that generates under my average daytime use is only going to benefit me at that rate. However, a bigger system that exceeds my daily usage will benefit me at $0.52 / kWh and my return on investment in the rooftop PV system will be much better.

We’ve booked in a couple of PV installers to come take a look at our new house on September 3. I’ve not settled on a system size yet but I have settled on the components, Suntech mono-crystalline panels and a Sunnyboy Inverter. These are reputable brands that should just work. No point skimping on quality on a system that will cost multiple thousands of dollars whether a good quality or rubbish brands are used. More on this later.