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

10:07
7 November 2022

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

Rjukan
Rjukan, 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
Turbulent conditions in southern Europe. Severe thunderstorms. . . Monday 24 August 2026
Weather map shows a risk of severe weather in parts of France and Italy, amongst other places
Monday 24 August 2026

Severe thunderstorms

Turbulent conditions in southern Europe
Damage in Germany after severe weather. Several tornadoes formed. . Weather Videos. Thursday 20 August 2026
Split image: Weather map showing thunderstorms and a tornado symbol over western Germany. On the right, severe damage to buildings and rubble on a road can be seen.
Weather VideosThursday 20 August 2026

Several tornadoes formed

Damage in Germany after severe weather
Record warmth in the Mediterranean. High water temperatures. . . Tuesday 18 August 2026
Split graphic showing a hot southern Europe temperature map beside a sunny Mediterranean beach, with a sea-temperature icon highlighting very warm coastal waters.
Tuesday 18 August 2026

High water temperatures

Record warmth in the Mediterranean
All weather news
This might also interest you
A frozen start to the weekend. Icy conditions. . . Friday 13 February 2026
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
Bright and warm conditions take hold. Spring-like outlook. . . Thursday 23 April 2026
Split UK map showing warm temperatures up to 21 degrees in orange on the left and clear sunny conditions with temperatures from 12 to 18 degrees on the right, with sun icons across the country.
Thursday 23 April 2026

Spring-like outlook

Bright and warm conditions take hold
Historic Storm Éowyn arrives. On this day.... . . Saturday 24 January 2026
Split image showing a person in a yellow jacket struggling against strong winds and heavy rain on a street at night on the left, and an Irish wind forecast map on the right with red and purple shading, gusts up to 75 mph, and a wind warning icon, divided by a curved white line.
Saturday 24 January 2026

On this day...

Historic Storm Éowyn arrives
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