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
Two-part map of Europe showing temperature distribution: on the left, high temperatures above 30°C in France, Germany and Italy; on the right, significantly cooler with temperatures below 20°C in London, Brussels and Amsterdam. A white arrow between the maps marks the change in temperature.
Tuesday 19 August 2025

High summer bids farewell

Temperature changes in Europe
Split image of a vineyard on the left. Weather & Radar reporter stands with vineyard owner on the right holding bottles of wine.
Tuesday 19 August 2025

Flashback

Warming Isles good for vineyards
Monday 18 August 2025

Cloudy week

Understanding clouds on the WeatherRadar
All weather news
This might also interest you
Temperature radar showing the UK and Ireland. Warmest in the east where a red thermometer is shown. Cooler in the west where a blue thermometer is shown.
Wednesday 13 August 2025

Breakfast brief

Cooler under clouds, still hot in places
Weather map showing a split in north-south conditions of the UK. Scotland sees widespread cloud cover while England and Wales have clear skies.
Friday 15 August 2025

Clouds on the move

North-south split in conditions
Friday 15 August 2025

Breakfast brief

Split with cooler north, hot south
All articles
Weather & Radar

www.weatherandradar.ie

facebooktwitteryouTubeContact uslinkList
Privacy Policy | Legal info | Accessibility statement