I'm not sure an all-day sun facing roof (here in Australia it's North-ish :-) is as important as you might think. My house is very narrow running North-South s

I'm not sure an all-day sun facing roof (here in Australia it's North-ish :-) is as important as you might think. My house is very narrow running North-South so I have two sets of panels facing East and West instead. Does that mean I get a perfect peak output during the middle of the day? No. But my generation comes on earlier and off later than friends with perfectly aligned systems - which without a powerwall (sadly don't have one yet) that is a benefit expanding the amount of time that I am generating usable power and saving A$0.25c/kWh instead of earning $0.06/kWh for exporting it at peak generation. (fair that in this context we're looking at potentially having a power wall too, but never the less - you lose round-trip efficiency on batteries - about 10% - it's likely to end up fully charged anyway depending on your daytime usage and thus extending your generation time might still be good). I have 3.5kW of panels (3kW inverter, the max I can get on a single phase supply) and hit about 2.75kW peak generation . I wouldn't mind adding another panel or two per string (on my particular inverter and due to having two parallel strings, it works out fine for the voltages.. but this can vary a lot depending on your system specifications) </end of not totally scientific ranting> But also - seriously, the aesthetics. My suburb (Baldivis, Western Australia) has one of the top solar penetrations in the entire country at 57% of all houses (you can see here, it's 5th on the list: http://reneweconomy.com.au/australias-top-solar-states-and-suburbs-23048/ http://reneweconomy.com.au/australias-top-solar-states-and-s...) -- and while they're not exactly drop dead UGLY - it sure would be prettier with roofs like this everywhere. Particularly here we have a lot of smaller houses in orientations which mean often they end up being street facing instead of not. So yeah. Not sure how much of a greenhouse effect your roof is going to end up with though, that will be interesting. (here, we have predominantly tile or tin roofing - this shingle like stuff is much less common here than other parts of the world from what I've gathered)