View of the 1992 main array of 36 / 64W amorphous panels and second array July 2015 9 / 250W = 5.28kW total
I believe this was the first domestic array of photovoltaic panels to be erected in the ACT. It was so new that when I enquired at Planning and Land Management (PALM) in 1991 the staff did not know what I was talking about so I just went ahead and did it. I did a thorough analysis of the merits of crystalline v. amorphous panels and concluded that the greater tolerance to summer heat and the absence of glass covers were advantageous. My total array (incl. the CHP1 panel outside our bedroom is 2.94kWp which has proved adequate for our reduced circumstances). The second array in July 2016 added 2.25kW.
64W United panels (made in Mexico) were the biggest available at this early time and 36 panels were bought (@$14/W. They are now in 2015 down to about 50c/W). Nevertheless, as I was fixing them myself with Dexion galvanised angles well screwed down to the roof battens and trusses I was able to save a substantial amount. They were fixed at 16º tilt above horizontal with a generous ventilation space, thus providing good shade cover to the roof area. Ample access space was provided to allow easy cleaning and all screw fixings to the corrugated steel roofing were well silicone – no leaks have ever been found.
I could have fixed them at a steeper angle to gain better absorption (only about 2% better) but I didn’t wish to have them looking aesthetically awkward at a higher altitude, thus putting other people off installing such a valuable technology.
I clean them about once a year which seems to be adequate and after 23 years there is very little reduction in generation. They are guaranteed for 20 years and it is thought that they would have a 30 year useful life – but nobody really knows.
My records indicate that I have been receiving about 3-3.5 MWh of generation every year with about x % being exported to the grid @ 55c/kWh for 20 years. The 19 Jan 2016 account showed that we generated 6.2 times more than we consumed in Sept-Nov.2015 which is good news for the environment and for our pockets.