Owing to their sheer physical size, wind turbines and wind farms can be detected by radar systems. Yet decisions that are made regarding the likely impact that a wind farm may have upon radar operations are currently based upon hypothesis. The electromagnetic interactions between a wind turbine and a radar signal are complex and there is currently limited understanding in this area and no accepted method for quantifying this potential impact.
For that simple reason, many organisations have raised objections to the development of new wind farms simply because of the potential compromise to aviation safety that they pose. According to 2002 figures from the British Wind Energy Association (BWEA), for example, more than 25% of all proposals for wind farm developments were the subject of objections from radar operators at the pre-planning consultation stage.
As part of a range of initiatives aimed at tackling these issues, QinetiQ has completed a DTI funded study, commissioned as part of the work of the Working Group for Wind Energy, Defence and Civil Aviation Interests, that provides a more detailed understanding of the interactions between wind farms and radar systems.
Part of the study involved QinetiQ developing and validating a computer model that can be used to predict the impact of wind turbines on radar systems.
The model was successfully validated through a full-scale trial by using a QinetiQ mobile radar system to collect data far an operational turbine at Swaffham in Norfolk. The validated model was then used to perform a detailed investigation of the key factors that affect the interactions between wind turbines and radar systems.
The results from the study have already provided wind power and aviation communities with a more detailed understanding of the complex interactions between wind turbines and radar systems than were previously available. Looking to the near future, the model has the potential to be a valuable tool during the wind farm planning and consultation process.