Lightning bolts love wind turbines a little too much

Scott K. Johnson

The engineers and operators who run wind turbines are acutely aware that one can easily have too much of a good thing. Windy days mean lots of generation, but the turbines can be severely damaged if the wind velocity is too great, so they must be carefully managed. That’s not the only thing a wind turbine has to look out for, though. Being such tall objects, they stick their heads high above their surroundings, and in doing so they are likely targets for lightning strikes. Most of the time, that electrical energy is safely carried to the ground with the turbine no worse for the experience, but certain types of powerful lightning strikes can result in costly damage.

In fact, wind turbines seem to attract more than their fair share of lightning damage as compared to buildings and towers of a similar height. This has prompted research into why that might be and how turbines could be better protected. The distinguishing characteristic of a wind turbine as compared to, say, a cellular tower is obviously the giant, whirling blades. So what are the blades doing?

To see what was going on, Joan Montanyà and Oscar van der Velde of the Universitat Politècnica de Catalunya in Barcelona and Earle Williams of MIT set up an array of radio sensors spaced kilometers apart around an area with several wind farms in Spain. The system maps the location of lightning radio emissions in three dimensions.