Giant mirrors to lighten up dark valley town in winter.
Since its founding a century ago, a factory town in Norway has gone without direct sunlight for six months of each year—until now. A new set of mountaintop mirrors is beaming sunshine into the town square.
Rjukan, a community of 3,500 in the Telemark region of southern Norway, sits in a deep valley, running from east to west, in order to provide homes for workers at a massive hydroelectric plant and other factories that operated for most of the 20th century. The price that its residents paid for their prosperity was a half-year in the shadow of the mountains, from 28 September to 12 March.
In 1913, the founder of both the Norsk Hydro company and Rjukan, Sam Eyde, proposed placing a mirror up in the mountains to bounce sunlight into the town during winter. No one followed up on his idea, although the company built an aerial tramway to take Rjukan residents up to the mountain peaks to get some solar photons.
Ten years ago, artist Martin Andersen moved to Rjukan and noted the lack of sun. After years of fundraising, his campaign to build a Solspiel or “sun mirror” concluded at the end of October, when it went into operation.
The Solspiel consists of three solar-powered, computer-controlled mirrors, each 17 m2 in area, sitting at an altitude of 742 m above sea level, or about 450 m above the Rjukan town square. Together they reflect more than 80 percent of the gathered light down to the town square, to make a sunny patch in which residents can bask.
Andersen served as project manager for the design phase of the Solspiel project, according to Karin Rø, the community's tourist manager. Engineering firms Devotek (Norway) and Bilfinger (Germany) managed the 5-million-krone (U.S. $810,000) project with heliostat technology from Solar Tower Systems GmbH (Germany), mostly used for solar-power farms.
“Looking up to the mirrors is like looking up to the sun—you are not able to do that for more than a half second,” Rø says. No warning sign has been posted, but townspeople seem to understand the danger of staring directly into the reflected beam.
Since the Solspiel is new, there are no plans yet to add more mirrors to bring sunlight to a wider area of Rjukan. “but you never know,” Rø adds. “This was a crazy idea we have realized. We are proud to have made it, and we have got a lot of attention!”