For reasons of aviation safety, wind turbines in Germany with a total height of more than 100 meters must be marked at night with light signals. However, many people consider the flashing lights a disturbance. This is why the Projekt Group threw its weight behind needs-based nighttime marking at an early stage. It did this through the commitment of Roland Hagendorff, spokesperson of the "Marking" working group of wind energy association Bundesverband WindEnergie, and through many years of painstaking work that has turned needs-based nighttime marking into reality.
All flashing lights are only switched on when an aircraft approaches at a "warning-relevant altitude" of below 600 m. In the municipality of Ovelgönne , which together with the Wesermarsch rural district supported the project right from the start, the company Quantec operates an NBNM aerial surveillance system which transmits signals that are reflected by approaching flying objects. The signals received are used to calculate the aircraft's flight path so that marking lights are immediately switched on if it comes near.
Extensive groundwork had to be laid before this system could be used in the Oldenbroker Feld wind farm. This included a general approval of the NBNM system, a conformity declaration from German air traffic service Deutsche Flugsicherung (DFS) and a location-specific approval from the State Aviation Authority based on a DFS report. Now, after all the required approvals have been obtained, the Oldenbroker Feld wind farm is one of the first in Germany to use needs-based nighttime marking. Further wind farms in the 800 km² surveillance area of the Quantec NBNM system will follow.
"People used to use the expression "dark Germany" to describe the GDR because of its poor street lighting, often bleak architecture, general lack of colour and air pollution caused by the intensive burning of lignite. We're giving the expression a new meaning", says Ubbo de Witt, a managing partner of the Oldenbroker Feld wind farm.