Home / Editor's Pick /

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

10:07
7 November 2022

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

RjukanRjukan, known for its perpetual darkness in winter, is located in the bottom of a valley between steep mountains. It only gets sunlight reflected by giant mirrors on the mountain - © picture alliance

While the days across the UK and Ireland are getting noticeably shorter, 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 towns factory workers.

Instead, a tramway, that is still in operation today, was built to give employees and their families access to the sunshine. In 2005, Eyde’s mirror project was revived by Martin Anderson.

Eight years later, 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.

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.

Weather & Radar editorial team
More on the topic
Weather map of Europe with high and low pressure areas marked. Isobar lines show the pressure distribution, alongside a forecast map. Different weather conditions from northern to Southern Europe.
Monday, 22 December 2025

"High over low"

Blocking weather conditions at Christmas
Weather radar showing clouds and showers over Algeria and Morocco. Next to it, a warning map with the rain area in Algeria marked. Surrounding regions mostly sunny and dry.
Thursday, 18 December 2025

Algeria affected

Rain in the desert
Weather map showing temperatures and a 4,542 mile route arrow over the Atlantic. Symbols indicate sun, clouds and precipitation from North America to Europe.
Wednesday, 17 December 2025

From Europe to America

Weather front over 4,500 miles long
All weather news
This might also interest you
plit image showing a double rainbow over a rocky shoreline on the left and sheep grazing in a green field under stormy clouds on the right.
Sunday, 2 November 2025

Your weather - Your shots

Mixed conditions on an unsettled week
Weather map of the UK and Ireland showing scattered showers with cloudy patches across much of the region, especially around western and northern areas. Sunshine symbols appear over London, Cardiff, and parts of southern England, while temperatures range from 17°C to 18°C in most places. Areas of heavier rain are visible over the Atlantic to the west.
Friday, 29 August 2025

Breakfast brief

Unsettled conditions into the weekend
Wednesday, 27 August 2025

Breakfast brief

Frontal system brings heavy rain
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

facebooktwittertikToklinkList