Light:Guard successfully tests on-demand night marking (ADL) in Denmark

Light:Guard GmbH has launched a new building in the Danish Wind farm Sønder Bork a pilot project for demand-controlled night marking (BNK). Over a period of six months, the light:guard system recorded reliably detected flying objects and documented how often the obstacle lights would have been eliminated under the current Danish framework . The evaluation shows a theoretical light-off time of 97.4 % at 98.7% system availability.

BNK reduces the flashing of wind turbines to a minimum. To do this, the system monitors the airspace around a wind farm. When a flying object approaches, it increases the suppression of the Lights on and the red light flashes as before.

In Denmark, the law that regulates the Needs-based switching off of obstacle lighting on wind turbines still in the design phase. Therefore, the project was initially operated exclusively in report mode. The lighting of the five turbines remained switched on, the shutdown was simulated virtually.

For this purpose, Light:Guard installed a Light:Guard receiver (LGR) that captures transponder signals from flying objects. While the receivers in German wind farms are usually located at 80 to 175 meters height above ground, the receiver in Sønder Bork could only be installed on ground level. The antenna was installed on the outside of the transfer station at a height of about five meters. According to the current state of knowledge, This is the lowest receiver installation for BNK in a single Wind farm worldwide.

The Danish requirements are set out in detection of flying objects from 300 feet, i.e. about 91 meters, over reason. The pilot project was therefore also a test of whether such a low receiver can detect aircraft at the required minimum altitude. This has now been proven to be the case.

"Not the first and certainly not the last pilot project that I have and even install it personally. Particularly unusual was the installation of the receiver close to the ground", says Light:Guard hardware specialist Heiko Nöldeke. "I am all the happier that the system is so runs smoothly and reliably detects flying objects."

Usually, in addition to the receiver installed in each wind farm, which monitors the lighting in the wind farm. Since this has not yet been legally regulated by the BNK system, developed Light:Guard for the pilot project a virtual light control unit.

This virtual LCU prepared the recorded data for reporting. This made it possible to understand how often the system was available and how long the flashing would theoretically have can be suppressed.

The Light:Guard receiver was released on 4. March 2026. On March 9, 2026, Light:Guard put the system into operation, since then, it has been recording the transponder signals of flying objects in the vicinity of the Wind farms.

For the analysis, the data from six months from March to September 2026. The light:guard system achieved an availability of 98.7 %. The theoretical light-off time was 97.4 % on average. The proportion of theoretical light-on-time and of the errors that occurred were minimal.

Sales agent René Aamand has not only legislation in Denmark for three years, but also the Project Sønder Bork: "With this case study, it was shown that the light:guard system can also be used under these special conditions: in a new regulatory environment, with an unusually low receiver installation and according to the detection requirements provided for by Denmark. Now we hope that the law will soon be passed so that the nights will also be dark in Denmark ."

The case study thus provides a reliable data point for the planned introduction of demand-driven night marking in Denmark. This is also not far away: the Danish authorities are working on the final draft law, which will come into force at the end of the year. is to be adopted.

Light:Guard is ready for this: "As soon as the law allows BNK in Denmark, we will darken the turbines at Sønder Bork wind farm, together with another wind farm. We hope to be the first in Denmark," Felix von Hammerstein, Head of Business Development at Light:Guard, hopefully.

The complete data is online Available at: https://light-guard.com/aktuell/fallstudie-bnk-im-windpark-sonder-bork-in-daenemark/.