Cool idea, there is a town in Austria where the sun doesn't shine in winter and they were going to build something like that on the adjacent mountaintop. I think it never happened, though.
More results here: https://kagi.com/search?q=rjukan+mirror&r=no&sh=jDluj1x6n_J8...
https://www.vice.com/en/article/epnvzn/viganella-italy-fake-...
[edit] Looks like a town in Norway did it as well, and theirs tracks the sun.
https://www.theatlantic.com/photo/2013/10/using-giant-mirror...