In winter time the south side, of an east - west street, remains in shadow all day. The ground on the north side of the street gets some sun, while the upper stories of the south facing buildings, on the north side of the street, remain bathed in a golden radiance for most of the day. (assuming clear
skies of course)
If ice has formed overnight then it will linger on the south side of the street all day where as it often melts away on the north side. If we could reflect the energy falling on the walls of the south facing buildings down to ground level then the whole street, at ground level could have more sun light for longer, possibly helping to raise the temperature of the ground so that any ice there will melt and possibly inhibiting ice from forming the following night.
Using plain mirrors to reflect the light would have drawbacks, it would create many 'suns' potentially causing a hazard for motorists and inconvenience for every one else. So some element of diffusion would be needed. Would a frosted mirror work?
In order to get the best out of the sun the mirrors would have to direct light into the street over the longest possible time span. Reflecting it onto the upper stories of the buildings opposite is no good. Sun tracking, I think, is out of the question as it would make the system far to expensive.
So here is the question: To make this work a material that is capable of directing and diffusing a beam of light from a moving source into roughly a constant place. Of course in winter (northern hemisphere) the sun describes quite a flat path across the sky so this might not be a problem.
any thoughts, fellow demi boulangers?