https://www.youtube.com/watch?v=4NRR2HpALhM
The town of Viganella in the Italian Alps receives no direct sun for 83 days each year. So in 2006 mayor Pierfranco Midali commissioned a 26-by-16-foot mirror to be placed on a nearby mountainside at 3,600 feet. Tracking the sun with computer-controlled motors, the mirror throws light into the town square for six hours each day.
The illuminated area measures 300 square yards. “I can already see my little old ladies coming out of the church after mass and just standing there, enjoying a bit of sun,” Midali said.