The City of Porvoo, black square on back is the church of this town Kimmo Huosionmaa Silicon solar panels are all black, and they have been used in satellites long time. They would transfer the light to the electricity, and those panels are extremely lightweight. But they are also very easy to install on the roofs, and no outsider would ever notice that on the roof is installed solar panels. The answer for installation problems is that those panels would be drilled the holes in the factory, where screws or nails can be put, and the installation of those elements is as difficult as a normal roof material. Those solar panels would be covered by bulletproof glass, what would be protected the silicon layer. The electric wires might be pulled inside the house by the way, that they would not disturb the shape of the house. So this solution is suitable also for historic houses, which shape must not be broken with modern things. The problem has been holes, what must be drilled in...