In New York City, you’re lucky if all the rooms in your apartment have windows. There’s most likely a corner that never gets any sun. They know about lack of sunlight in Sweden, where Parans Solar Lighting is trying to bring natural sunlight into dark rooms and spaces — with fiber-optic technology.

The fourth generation of the system, called Paranslight SP4, debuted this week at the sustainable construction and energy EcoBuild exhibition in London. The company claims the fiber-optic cables of this system can filter in natural light for 30 floors of a building.

“Our philosophy is simple,” says Nils Nilsson, the CTO of Parans, “use sunlight first, and artificial when you must.”

The company hopes Paranslight SP4 will be installed in skyscrapers and deep tunnels — the system causing little alterations to the structure of properties.

The cables of the fourth generation reach up to 100 meters, which is 85 feet more than the longest cable the third generation could support. The third generation could collect 6,000 lumens (approximately 100,000 watts) from an outdoor illumination of 100,000 lux. However, the receiver uses about seven watts of electricity. One SP3 fiber-optic cable creates about 350-700 lumens, depending on the length.

A diagram of the third generation of Paranslight system.

Engineers at Chalmers Technical University in Gothenburg, Sweden, have been developing the technology since Parans was founded in 2002. The first patented technology was released in 2004, according to TechCrunch. Parans was also awarded €31,000 for winning the World Wildlife Fund (WWF) Carl Mannerfelt Prize in 2008, which recognizes organizations that help nature conservation and environmental control.

Photos via Parans, Chalmers University of Technology/Rebecca Hallqvist/Magnus Renstrom, Karen/Flickr