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
Europe's summer set to to break records. Extreme heat and drought. . . Tuesday 11 August 2026
Split image showing a European heat map with temperatures reaching 39°C in France and Spain on the left, and a severely depleted river with exposed sandy banks beneath a bridge on the right.
Tuesday 11 August 2026

Extreme heat and drought

Europe's summer set to to break records
Getting through the latest heatwave. Tips to beat the heat. . . Tuesday 11 August 2026
Split graphic showing temperatures up to 35°C in England and 28°C in Ireland beside a person applying sunscreen, with a heat warning symbol highlighting hot weather.
Tuesday 11 August 2026

Tips to beat the heat

Getting through the latest heatwave
More comfortable night's sleep. Overnight low drops. . . Wednesday 5 August 2026
Morning temperature map of the UK and Ireland showing cool conditions, with temperatures ranging from 7°C in South Wales to 13°C in southeast England. Ireland records 9–12°C, while much of England and Wales is between 8°C and 10°C. A blue thermometer icon highlights the cooler weather.
Wednesday 5 August 2026

Overnight low drops

More comfortable night's sleep
All weather news
This might also interest you
Super Typhoon Bavi threatens Taiwan. Up to 1,000 mm of rain. . Weather Videos. Wednesday 8 July 2026
The image shows an intense tropical cyclone over the western Pacific, east of Taiwan and the Philippines. The centre of the system is depicted as a light purple and white vortex with a clearly visible eye, surrounded by a ring of red and orange areas indicating the strongest wind speeds. A white arrow marks the typhoon’s predicted track towards the north-west, in the direction of Taiwan. To the west of the storm lie the Philippines, with the cities of Manila and Cebu; to the north of these lies Taiwan, with Taipei. Further west, the Chinese coast, including Hong Kong, and parts of Vietnam can be seen. The coloured wind map shows predominantly green areas outside the storm’s core, indicating significantly weaker winds. White streamlines illustrate the typhoon’s anti-clockwise circulation in the Northern Hemisphere. The highest wind speeds are concentrated around the eye of the cyclone.
Weather VideosWednesday 8 July 2026

Up to 1,000 mm of rain

Super Typhoon Bavi threatens Taiwan
Long-term trends need a pinch of salt. 40 °C in July?. . . Tuesday 30 June 2026
Temperature radar of 2022 heatwave where the all-time temperature record in the UK was set. Warning symbol overlain.
Tuesday 30 June 2026

40 °C in July?

Long-term trends need a pinch of salt
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