Finns have a short summer season with very long hours of daylight at a low sun angle so they need to try every possible trick that will help. These are self-built panels, and seem to use central heating radiators as collectors. I hear from Sami that winter temps are so cold up there that you have a risk with above ground liquid circuits, even with anti-freeze. As the winter photo here shows, there probably too much snow for them to work even if you did have plenty of anti freeze in them!
Aurinkovoimaa is Finnish for Solar Panel. Well done to Jussi for believing in the power of the mirror! His other albums have pictures of boat restoration projects, car and heat pump reconstruction, and more. He seems to have a very large workshop.
His Picasaweb album has pictures of the whole thing being built in the workshop - the link is: