RE: Color-changing roof tiles can absorb, reflect heat with the seasons
I also like the idea of polymer based photovoltaic cells printed on the same presses that Australian currency currently uses for producing a roof filled with photovoltaics. I believe that the efficiency is now fairly poor, but improving,but the cost is low. The idea being presumably to produce electricity producing roof tops that can be marketed much the same way and for much the same cost that colourbond roof sheeting is currently produced for.