There shall be light - and mirrors

The Norwegian town of Rjukan, surrounded by mountains, has set up mirrors to combat winter darkness. The 3,500 residents in the valley town some 180 kilometers (110 miles) from Norway's capital Oslo virtually didn’t see the sun for about six months as it never reached the valley from September until March.

Mirrors erected on a mountainside deflect sunlight into the valley town. It's an idea that has been around for a while: Norwegian industrialist Sam Eyde came up with the concept some hundred years ago but lacked the proper technology to succeed. Instead, Rjukan built a cable car for people to temporarily escape the town's darkness.

In 2005, local artist Martin Andersen picked up Eyde's idea and has now brought the project to fruition. Three separate mirrors, totaling 51 square meters (549 square feet), were installed approximately 450 meters above Rjukan's market square. This heliostat runs on wind and solar energy.

Rjukan's heliostat has two axes on which it moves; a computer program follows the sun's path during the year. Sunlight reflected onto the market square has an elliptical shape of 600 square meters. Costs for the project accumulate to five million Norwegian Krone (620,000 euros; $850,000).

For other regions in Norway, mirrors won't do the trick. Above the Arctic Circle, there are days where the sun never shines. Although polar nights are not completely dark, these polar nights last in northern Norway for about two months. During summer, the sun never sets for two months.

Rjukan is not the first town to use mirrors to deflect sunshine. Here, an eight-by-five meter (26 by 16 feet) mirror helps illuminate the Italian village of Viganella in the Alps. Surrounding mountains cut off direct sunlight during the winter here, as well. Viganella set up its mirror in 2006.

A family in the tiny village of Wildgutach in Germany's south was struggling with lack of sunshine as well. Their farm was left in the dark from mid-October until mid-February. In 2010, they decided to put up a small mirror of 2.5 by 3 meters (8 by 10 feet) to combat the shade.

Compared to the dimensions on Rjukan's town square, the German family's contraption doesn't bring much more than a few rays of sunshine. But it's just enough to help them through those otherwise dark winter days.