Geoscience Australia has other useful information on their web page, such as lat/long for various places, sunrise and sunset times.
Just type in your suburb name and you can get answers more accurate than the city centre - in my case the nearest listed place is over the back fence.
I ordered a PV system one month ago. With a 7 degree pitch roof I have chosen to put the panels flat on the roof with about 7% reduction in output compared with the optimum tilt. Panel size is 1600x800, and the roof batten spacing is 900, so there will be a 200mm gap between rows of panels, allowing access for cleaning. Aesthetically I think it looks better without angled frames. I was interested to see details of the roof mounting system. The existing roof screws are removed. A rubber pad is placed over the screw hole, then the aluminium L bracket, then a new screw with a nylon washer is put in the existing hole. The rubber pad prevents metal to metal contact between the zinc/steel roof and the L bracket, and the nylon washer prevents metal to metal contact between the screw (which will touch the roof) and the L bracket. So hopefully there won't be any corrosion problems between the aluminium mounting hardware of the panels and the Colorbond roof.
I've seen the result of an ordinary steel self tapping screw being used to attach a jib halyard to an aluminium mast, and it left huge corroded hole when it ripped out while sailing.
Going off the original topic even further, can you describe your active and passive hot air systems? Hot air doesn't have a good heat storage capacity compared with water. On sunny days our house heats nicely through the windows, except for the south facing study. I have added an active system (Solarventi) to heat that room, which worked well through spring and is now turned off.
Posted Friday 4 Dec 2009 @ 2:40:56 am from IP #