Evaluation of the Mutual Lightning Shielding Effect on Onshore Wind Farms

We evaluated the influence of the relative position of wind turbines (WTs) on the number of lightning strikes based on lightning data collected by the METEORAGE lightning locating system. We analyzed a total of 219 WTs distributed in 30 wind farms located in three regions in France with different characteristics in topography and lightning activity. We observed that 67 % of outer WTs are the most affected by lightning compared to the inner ones, this ratio decreasing when wind farms are set on a complex terrain. We noted that an outer WT cannot be top ranked when either the separation distance with its neighboring WT is getting large or the total height of a WT inside the wind farm is higher than its. The analysis of the number of strikes on isolated WT set at low altitude showed high values comparable to those for the outer WT in wind farms located in the same region. Finally, we observed that on average outer WTs are 3 times more lightning struck than its neighbor in the cases where both WT are located at the same altitude. We concluded, these results demonstrated the mutual lightning shielding effect confirming some other works stating this effect is mitigated for wind farms set in altitude.