Not my roof, but similar system
Almost two years ago I installed solar collectors on our Edmonton home and garage. Neither location was perfect- one facing WSW rather than South and one partially covered with shadow from trees an a neighbouring house. Nonetheless, I was able to install 20, 385 watt panels for a total capacity (under full sun) of 7.7KW. The total cost was around $18,000 Can and I received about $4,000 government incentive – so $14000 investment. For the first few months I stuck with my old supplier and saw minimal returns and terrible documentation of my micro-generation.
So last year I switched to a small energy coop the Alberta Cooperative Energy which has a great deal for micro-producers. I sell (and buy) electricity to the grid at a much higher rate ($.25 KWH) when my collectors are producing during the summer- yielding a nice monthly payment. During the winter I revert to standard rates in Alberta (~.06 KWH).
The annual bills from ACE revealed that we had used 5.940 MWHs from the grid and generated 5.950 MWHs to put back in! Self sufficiency – sort of. Of course in dark and cold Northern Alberta winter, we were consuming much more than we produced.
A further look at bills showed the financial payback detail. The first full year produced an annual return of 5.56%! Too bad the panels were snow covered for 4 months!
This return is tax free and appeals to my inherently frugal mentality.
I hope this data inspires others to make their own solar investments.