Wind Turbines Can Generate Lightning Via Movement Of Turbine Blades

Given the right conditions, wind turbines can generate lightning (for reasons other than simply being elevated), new research from the Universitat Politècnica de Catalunya (UPC) has found. The relatively fast movement of the wind turbine blade tips directly triggers electrical discharges, according to the work.

The researchers think that their new findings will be useful in the creation of protocols and systems to help limit the damage caused by such phenomena. Millions of euros of damage are caused to wind turbines every year by lightning, according to the researchers — primarily to the blades, which are typically made of a composite material sensitive to the effects of electric discharges and lightning.

Lightning on the Rubió wind farm.
Image Credit: Universitat Politècnica de Catalunya (UPC)

The press release from the UPC provides more:

The UPC Lightning, Atmospheric Electricity and High Voltage Research Group’s (LRG) new work relied on its lightning mapping array located in the Terres de l’Ebre region of Tarragona — and via this array the researchers were able to detect periodically recurring electrical discharges from the wind turbines that we’re being monitored. The duration of these discharges varied from around every few minutes, to over an hour, depending on the storm conditions at the time.

Researchers have made high-speed video recordings of lightning flashes caused by wind turbines on the Rubió wind farm. The LRG, which is a European benchmark in lightning studies, has recorded several upward lightning flashes caused by rotating wind turbines under clouds. These recordings were made at a distance of one kilometre from the wind turbine, with the camera set at a speed of 6668 frames per second and a resolution time of 150 microseconds.

With regard to why this work is important, as stated before, lighting can be quite damaging to wind turbines. “Depending on the region in which the farm is located, the damage can be severe. On the west coast of Japan, for example, winter lightning is far more harmful than summer lightning. In fact, some wind farms have been forced to close because of storm damage.”

I’m not sure what will be done about the issue, especially given that the problem comes from the (very necessary) movement of the blades, but characterization of the phenomena is no doubt a good first step.