How an Immense Sun Mirror Lights Up Norway’s Tiny Rjukan

by Kids Discover


What would you do if you lived in a town so deep in a valley, the sun didn’t even shine there half the year? What? You’d move away? Okay, let’s say you didn’t move. Let’s say you liked it in Rjukan, Norway — or at least needed people to stay there.

That’s the situation that faced Sam Eyde, a Norwegian industrialist who built factories in this dark valley more than 100 years ago. A pioneer in Norway’s chemical industry, he also developed an enormous power plant to harness hydroelectric power from the nearby Rjukanfossen waterfall.

So he built Rjukan in the nearby valley to house people who worked for him. That worked well for half the year. But from September 28 to March 12, the sun basically skips town, leaving almost six months of shade and night.

Way back in 1913, one of Eyde’s factory workers suggested that big mirrors on the mountaintop could reflect the sun’s rays down onto Rjukan, deep in the valley. But the mirror technology wasn’t ready yet, so in 1928 Eyde built a cable car to take people up to the sunny mountaintops. People got used to it.

Fast-forward to a new century. In 2001, artist Martin Andersen moved to Rjukan. He revived the mirror idea — calling it a Solspeil (sun mirror) — and by then, the technology was closer to ready. (A village in Italy set up a similar system in 2006, and a stadium in Arizona uses mirrors to shine sunlight onto grass that grows in a shady area.) Interestingly, many Rjukan locals weren’t happy about the mirror idea — until it became a reality in 2013.

That’s when three twenty-square-yard mirrors went into action. They follow the sun all day, powered by solar energy and controlled by computers. A brilliant pool of light — about 80-90% as strong as direct sunlight — warms the town’s central square, where people gather together in the sunlight. It’s changed the town. Even skeptics like it now. And it’s attracting tourists — a valuable commodity in a town that long ago lost the industries that once drew folks to this dark valley.


Kids Discover For over 25 years, we’ve been creating beautifully crafted nonfiction products for kids. With a specialty in science and social studies, our team of talented writers, award-winning designers and illustrators, and subject-experts from leading institutions is committed to a single mission: to get children excited about reading and learning.


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