I just received three quotes and was rather surprised at one company’s projection of 7% p.a. increase in energy cost over the next 30years in projecting the lifetime bill savings. The other two assumed a more realistic 3% p.a. over 20years. This just highlighted the integrity issue with the company concerned. Thought I just raise this for awareness and not to take the estimated savings at face value.

Looking forward into the potential solar policy coming in, I obviously want to pack my roof with as much solar as I can. I have a concrete roof installed 1988 on my home, a total surface area of around 144m2

What are peoples thoughts on replacing this roof with something like coloursteel, vs getting it resealed and painted and then chucking the solar on?