Home
Weather Dublin
WeatherRadar
RainfallRadar
TemperatureRadar
WindRadar
LightningRadar
Weather News
Editor's Pick
Discover the app
Weather widget
Contact us
Apps
Home / Editor's Pick /

In the base of a valley: A town that uses mirrors for sunlight

18:00
24 November 2024

In the base of a valley
A town that uses mirrors for sunlight

A large mirror on the side of a mountain reflected sunlight towards a town in darkness due to its location within a valley.
Giant mirrors reflect sunlight towards the dark town of Rjukan. - © picture alliance

The days may be getting shorter, but at least we get natural sunlight, unlike a town in Norway that relies on mirrors to bring the sunshine.

Located at the bottom of a steep valley surrounded by mountains, the tiny town of Rjukan does not see sunlight for seven months of the year.

Rjukan was built between 1905 and 1906 by Sam Eyde. It was Eyde who dreamt of a giant mirror in 1913 to provide sunlight for the town's factory workers, though it took until 2013 that it became a reality.

Three 182-square-foot mirrors controlled by computer-driven motors were installed to bring a 6,500 square foot area of winter sunshine to the town.

The mirrors are able to bring 80-100% of the sun’s light to Rjukan by tracking the movement of the sun and repositioning themselves every 10 seconds to keep the light consistent.

Sunshine hours

Track sunshine hours near you with daily sunrise and sunset times in the astro card. 

Although the mirrors are unique, Rjukan’s were not the first. In December 2006, the town of Viganella in Italy’s Antrona Valley celebrated a day of light after a steel sheet was installed to reflect sunlight between November and February.

Why do the clocks change?read more
Ryan Hathaway
More on the topic
Sunday 3 May 2026

Reading the radar

Clouds on the WeatherRadar
On the left, a map of Europe shows temperature anomalies in April, with positive values in Western Europe and negative values in Eastern Europe. On the right, an industrial area can be seen, with chimneys and trees in the foreground.
Friday 8 May 2026

Record in Spain

Third warmest April on record
Silhouette of a person sitting beside a telescope on a tripod under a clear night sky filled with dense stars and the bright band of the Milky Way.
Friday 1 May 2026

May astronomy outlook

The only Blue Moon of the year rises
All weather news
This might also interest you
Weather graphic showing rain and wind fields over the Canary Islands and a central warning symbol.
Friday 12 December 2025

Storm and rain

Turbulent weather in the Canary Islands
Outline of Santa Claus with a yellow and white hat, "Ho-Ho-Ho" next to the outline above a Christmas tree.
Thursday 25 December 2025

Merry Christmas!

Wishes from Weather & Radar
UK temperature map dated 14.02 showing widespread subzero values in blue shading, with readings such as −4 in Glasgow, −3 in Dublin, and −2 in London, alongside a blue thermometer icon.
Friday 13 February 2026

Icy conditions

A frozen start to the weekend
All articles
Weather & Radar

Weather & Radar is also available on

Google Play StoreApp Store

Company

Contact us Privacy Policy Legal info Accessibility statement

Services

Uploader

Socials

facebooktwitteryouTubelinkList