In Norway, there is a town call Rjukan which is located by Lake Tinn it is a very picturesque place and one of the engineering feats. Their town’s founder Sam Eyde was an engineer who was able to harness the power of a 100-meter waterfall to provide the town with an ample supply of hydro-electricity. In fact, it was at one point the world’s biggest power plant.
But Rjukan had one crucial problem, it was completely surrounded by steep mountains, meaning that for half of the year the 4,000 inhabitants live in a shadow. From late September to mid-March is in a constant shadow with no natural sunlight, as you can imagine this is quite dull and depressing.
Rjukan is located at the bottom of a valley and the Gaustatoppen mountain rises high above it at 1883 meters, blocking out the sun completed. In 1913, Sam Eyde actually had the idea of building what he called the sun mirror, which he believed was a vital commodity for the survival of their town. For his workers to be happy, they needed to feel the sunlight on their skin.
But his idea never came to light, when he passed, his family decided a better solution was to simply build a gondola up to the mountain tops where the sun shined. Today this gondola is actually still functional and serves as a vital transportation link to other towns.
In 2013, the decision was made that the technology was finally here to make the sun mirror a reality. On top of one of the steep mountains, a computer-controlled heliostat was installed, at about 400 meters above the town. And on this heliostat, many 17 meter mirrors were installed, with the goal of reflecting the sunlight down onto the town.
The heliostat is able to tilt and spin, allowing the mirrors to follow the daily sunlight and reflect as much as possible onto the town’s market square. Even better, the device itself is powered by sunlight and wind meaning this device is environmentally friendly.