Here is the refurbished copper tip of a Vestus wind turbine blade.   Lightening is a real problem with tall, steel tower mounted wind turbines.  The lightening strike, if not conducted properly, can destroy the fiberglass blade and spot weld the turbine blade feathering bearing, the turbine rotor bearing, and blow out the generator and then zap the azmuthing bearings on the way down the tower.   That's a total of one huge fiberglass blade, three large rotary bearings and one generator at big risk.  Damage to any one of these components requires the turbine be shut down and most likely dismantled with a huge crane.