Mitigating wind turbine interference

Commonly used sources of energy such as oil and gas are diminishing. This is why the use of renewable sources like hydrogen, solar and tidal energy, biological gases, water and wind is rising. Many European states have increasingly ambitious renewable energy targets. In order to meet these targets, they will have to use renewable, sustainable ways of generating electricity – and wind turbines are useful devices for doing this.

Potential impact

Wind turbines can, however, potentially have a detrimental impact on the performance of surveillance systems used in air traffic control (ATC). A wind park with many wind turbines could create false targets or lose/corrupt information on an aircraft’s position. Wind turbines can be the source of electrical disturbances to ATC systems, mostly primary surveillance radars but also secondary surveillance radars, as they can generate a false track and cause the real targets (i.e. the aircraft) to be lost. Depending on their location, wind turbines can impact approach procedures. The usability of runways for instrument flight rules (IFR) traffic can be affected. With a possible height of more than 200 meters, wind turbines are threats for low-level flights.

The fact that wind turbines affect primary radars more than secondary radars, combined with the fact that military ATC controllers by law have to control their traffic based on primary surveillance data is the reason for the Military to have more stringent requirements to protect their surveillance radars than civil ANSPs.

Our contribution

In response to this and at the request of Member States, EUROCONTROL created the Wind Turbine Task Force (WTTF).

The WTTF was composed of civil and military representatives from European Civil Aviation Conference (ECAC) states, service providers and industry. Its mission was to define a common ECAC methodology to assess and avoid/minimise the potential impact of wind turbines on ATC surveillance systems whilst supporting the installation of wind turbines to the maximum extent possible.

Guidelines

A set of guidelines on “How to assess the potential impact of wind turbines on surveillance sensors” was made available in 2009 to propose possible mitigation measures against the impact of wind turbines on ATC radar surveillance. The approach followed was based on early and constructive dialogue, promoting reciprocal transparency between air navigation service providers (ANSPs) and wind energy developers.

In 2014 we released an update of the recommended methodology, which reflects the experience gained in applying the original methodology and includes provision for emerging techniques and technologies which can help alleviate interference issues.

A common, mutually agreed, methodology helps ANSPs maintain the necessary levels of safety by making sure that their surveillance systems are protected while supporting the installation of wind turbines to the greatest extent possible.

A group of experts constantly monitors developments and updates the guidelines accordingly. Nations are free to convert these guidelines into national regulations to form the legal basis for the approval /rejection of wind park construction around airports.