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

12:00
18 November 2023

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

Settings for external content

Privacy policy

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 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
The image shows the central Pacific in a computer model. A striking feature is the ocean coloured red, which indicates very warm seawater.
Wednesday 6 May 2026

Temperature records?

El Niño is gaining momentum
The map shows a thunderstorm and heavy rain warning over northern Italy and France. The affected regions are highlighted in colour.
Monday 4 May 2026

Heavy rain & storms

Risk of severe weather in the Mediterranean region
Silhouette of a person sitting beside a telescope on a tripod under a clear night sky filled with dense stars and the bright band of the Milky Way.
Friday 1 May 2026

May astronomy outlook

The only Blue Moon of the year rises
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
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
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