Wind Turbine Interference with Weather Radar

Weather radars collect information about targets (for example: rain, snow and insects) via pulses of energy that are sent from the radar antenna to the target. Some of the energy is reflected back to the radar. The measured energy provides information on the location and the intensity of the target. The radars used in Canada have Doppler capability which means they have the extra advantage of finding the velocity of the target. For more information about weather radars visit About Radar.

Environment Canada's visibility maps.
Environment Canada's visibility maps.

Interference from Wind Turbines

There are many things that can affect the quality of the data received by the radar. Objects such as buildings, trees, towers and terrain can block signals. These objects could result in the loss of meteorological information (such as the intensity of a storm located behind the object). Stationary objects have a zero velocity and can be filtered out of the data by the Doppler capability of the radar. However, wind turbines present new challenges to weather radars.

Wind turbines are tall structures composed of a fixed tower and multiple rotating blades. If a wind turbine was located close enough to a radar site, the tower could cause blockage and the radar would not be able to see anything behind the wind turbine. Apart from blockage issues, wind turbines have rotating blades which constantly change their orientation based on wind direction. This rotation is detected by the Doppler radar as an object with velocity. Turbines cannot be filtered out because the blades are moving. This kind of false information can be significantly misleading for forecasters under storm conditions.

Wind Farm Developers

Environment Canada is available to advise wind farm developers on potential locations which may interfere with weather radars.  A preliminary analysis can be done using the radar visibility maps. We suggest all developers contact us for assistance in a detailed analysis and potential mitigation options.

Please send an email to WeatherRadars@ec.gc.ca with the following information:

  1. Wind Project Name (of either the location or wind farm)
  2. Proponent or Consulting Firm
  3. Number of Turbines
  4. Tower/Hub Height
  5. Turbine Blade Sweep Diameter (or length of blades)
  6. Turbine Base Diameter (if known)
  7. Coordinate Locations of Turbine(s) (if known)
    - Latitude and Longitude coordinates given in decimal degrees format (or UTM coordinates with zone reference)