Outdoor lighting on nature’s terms

Käätyjärvi – A Unique Nature Destination in the Heart of the City

Uusikaupunki, and particularly its city center and harbor area, are renowned for their stunning scenery. Käätyjärvi is one of Uusikaupunki’s most valuable local nature sites. Opening up right next to the city center, the lake offers citizens a breathing space where the peace of nature meets the ease of everyday life. Käätyjärvi has been an integral part of local life for generations—its landscapes appear on Senate maps dating back to the late 19th century.

If anywhere knows how to appreciate history, it is Uusikaupunki. After all, the city boasts one of Finland’s best-preserved Empire-era wooden house districts. That is why decision-makers understood that the renewal of Käätyjärvi's area lighting required sustainable decisions.

LED lighting, of course – but how?

Cities in Finland and around the world have switched, or are currently switching, to LED luminaires. They save enormous amounts of energy and taxpayer money, but recent studies show that bright blue light significantly disrupts the circadian rhythms of wildlife.

Käätyjärvi's environment is particularly sensitive. It is classified as a valuable bird lake, and diverse wildlife thrives on its shores. At the same time, Käätyjärvi serves as a vital recreational area. The walking path circling the lake attracts outdoor enthusiasts, families, and exercisers in all seasons. In winter, people ski or tour skate on the lake ice; in summer, they enjoy the scenery and sounds of nature.

It is precisely this unique combination of daily life and nature that makes Käätyjärvi an irreplaceable part of Uusikaupunki's identity. However, it also posed a challenge for renewing the outdoor lighting:

"How do we implement lighting that enables human activities but ensures that the area's fauna and flora remain undisturbed?"

No cold blue light

Due to blue light, standard LED luminaires are by no means recommended for sensitive nature sites like Käätyjärvi. Fortunately for the residents and animals of Käätyjärvi, Uusikaupunki commissions its lighting design from Ari Nivola of Kalanti, who operates under his company name, Telener. Nivola proposed the acquisition of warm-toned luminaires for Käätyjärvi and successfully got the city planning department excited about the idea.

The Solution: Greenled Amber Nature Lighting

The Greenled Amber Nature Lens is a unique solution to a recognized problem. The lens installed over the light source practically removes the harmful blue light tone almost entirely.

regarding the light level, Uusikaupunki opted for a result slightly brighter than the old "high-pressure sodium yellow" tone, whereas a similar project at Pori Isomäki chose to use a very yellow tone.

According to Nivola, 58 Greenled Pegasus luminaires equipped with the Amber nature lens have been installed along the route, which runs for just over a kilometer.

"We installed standard six-meter poles, but were able to increase the pole spacing to 40 meters, allowing us to save on the total number of poles. The trees cast some shadows into the beam, but the route is now largely well-lit," Nivola describes.

While the nature lens is excellent specifically for nature sites, white light remains the superior solution for highways and main roads in terms of energy efficiency, significantly improving visibility and traffic safety.

Summary

Käätyjärvi’s lighting is now in order for decades to come, and the area's wildlife and nature will continue to bring vitality for future generations. Congratulations, Uusikaupunki – a domestic luminaire, especially one with a nature lens, is a sustainable choice.