Hello Solar Quotes, The information from your site and connection to potental local suppliers was very helpful. However, I did find some interesting things when researching the quotations I was offered. It would appeaar that the quotations were all based on the same or similar software (Pylon), so to that extent it made it easy to compare quotes. It was unclear how PV suppliers arrived at a different existing annual electricity cost when each was given the same current cost data for my residence. Also, and I guess this is in the software, the projected growth in residential electricity costs was shown as year on year growth of about 2-3% over the next 20 years, and this was based on a 2016 AEMO report. My review of the report (Figure 10) showed little or no growth in prices for my State (NSW) beyond 2030. If this is so then the household electricity cost projections are exagerated giving inflated ROI over time. Nevertheless I will be installing a PV Solar system because even on more conservative cost calculations the benefits should be realised in an acceptable timeframe. Thanks again, Colin Hockings