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
Two weather maps showing temperature extremes: −54 degrees in northern Asia and 45 degrees in Australia. Coloured areas indicate extreme cold and heat.
Wednesday 14 January 2026

Difference of 100 degrees

Extreme contrasts in global temperatures
Split image showing cars driving through heavy snowfall on a snow-covered road with low visibility on the left, and a UK weather radar on the right with blue and pink snow and rain bands, a low pressure system marked with an L, and snow icons near Ireland, divided by a curved white line.
Thursday 8 January 2026

Full impact overnight

Storm Goretti causing disruption
Split image showing suburban rooftops under a blue sky with two smooth, lens-shaped lenticular clouds on the left, and a snow-covered path on the right with footprints, trees lining the edge, and two dogs walking at sunset, divided by a curved white line.
Sunday 18 January 2026

Your weather - Your shots

Peculiar clouds as snow melts away
All weather news
This might also interest you
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
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
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
IE
Clima & Radar Brasil
Hava durumu & Radar Türkiye
Időjárás és Radar Magyarország
Καιρός & Ραντάρ Ελλάδα
Météo & Radar Belgique (Français)
Météo & Radar France
Meteo & Radar Italia
Meteo & Radar România
Météo & Radar Suisse (Français)
Meteo & Radars Latvija
OrasOnline Lietuva
Počasí & Radar Czechia
Počasie & Radar Slovensko
Pogoda & Radar Polska
Погода & Радар Україна (українська)
Tempo & Radar Portugal
Tiempo & Radar Argentina
Tiempo & Radar España
Vejr & Radar Danmark
Vreme & Radar Slovenija
Vreme & Radar Srbija
Vrijeme & Radar Bosna
Vrijeme & Radar Crna Gora
Vrijeme & Radar Hrvatska
Време & Радар България
Времето & Радар Macedonia
Weather & Radar India (English)
Weather & Radar United Kingdom
Weather & Radar USA (English)
Weather & Radar USA (Español)
Weer & Radar België (Nederlands)
Weer & Radar Nederland

Weather & Radar is also available on

Google Play StoreApp Store

Company

Contact us Privacy Policy Legal info Accessibility statement

Services

Uploader

Socials

facebooktwitteryouTubelinkList