Analysis of the cloud-to-ground lightning characteristics before and after installation of the coastal and inland wind farms in China

Abstract The effects of wind turbines (WTs) on cloud-to-ground (CG) lightning activities have not been fully understood. Based on the CG lightning data obtained from lightning location system (LLS), this paper quantified and compared the characteristics of CG lightning activities, including lightning density, multiplicity, polarity, peak current, and seasonal distribution, before and after the erection of the wind farms (WFs) in China. The shielding effect of offshore WTs was also analyzed. The results showed that, since the WF located in the southeast China was constructed, the return stroke density, flash density and multiplicity within a radius of approximately 0.5 km around the WTs increased by 27.9%, 7.3% and 10.9% in terms of change rate, respectively; within the same distance, the negative median peak current was -23.9 kA, and the positive median peak current was 12.3 kA. WTs located at the edge of the offshore WF had a shielding effect on the internal WTs. The proportion of spring lightning was up to 41.4% in southwest China. Winter lightning was rare in southern China. The results suggest more detailed factors, such as the local terrain, climate and the layout of WFs, are needed when assessing the lightning risk to WTs.