Federal: Aeronautical constraints for wind turbine installations in Belgium

Airports and aviation, in general, rely on radars to ensure that airplanes, helicopters and drones do not collide when flying. Tall, large objects placed directly in the vicinity of such a radar hinder its ability to "see" in the area behind the object. For wind turbines, the problem is worse, for in addition to creating a so-called 'blind zone', the spinning blades of the turbine are easily mistaken for airplanes, helicopters or drones by radars. Such radars are located anywhere where it is necessary to monitor air-traffic, such as the area directly in surrounding airports, but also in low-flying zones, around hospitals with helicopter pads, and military bases.

Generally, the area of 15 km surrounding the radar or airport is restricted. However, exceptions can be made if the proposed wind turbine installation does not negatively affect air traffic safety. It is also possible to minimise 'blind zones' by building other radars around the wind turbine installation. These large radar ports would be able to scan the area from another point of perspective and by communication with the airport radars, it would, in turn, resolve the blind zones. Still, this solution requires substantial financial investment and sufficient realisation time. There are debates about whom should bear the costs of these additional radars, but as of 2021, it seems unlikely that this solution will be adopted in the near future.

The issue presents itself in both Flanders and Wallonia. In Flanders the issue lies with the dense population and the numerous airports located in the region. Whereas, in Wallonia the issue presents itself in the form of restrictions near the numerous military bases located in that region.

While not solving the issue, however, in an effort to clarify the territorial restrictions for RES developers, Skyes, the Belgian air traffic manager, has created a map of areas which are off-limits for wind turbine development and areas which allow for wind turbine development of a maximum height of 210 m, pending assessment by the Belgian Civil Aviation Authority on the impact of air traffic safety.