Illustration of the right hand rule.
Lightning detection principle
When a lightning strikes a wind turbine a current will run through the tower while producing a magnetic field. As the current always flow through the bottom section of the tower, this is the ideal place to measure.
The measurement system can be either a pair of loop antennas or based on semiconductor magnetic field sensors attached to the outside of a wind turbine tower. The key point of measuring the current flow via the magnetic field on the outside of the turbine, is that the lightning will be detected in its entirety, including polarity, regardless if the lightning was partially or fully conducted via the surface of the blades, a direct strike into the nacelle, via lightning conductors or the turbine tower itself.
Jomitek has realised simple and extremely robust detection systems based on this principle.
See the classic products here or the Lightning Sensor & Analyzer here. Both products apply for all makes and models of wind turbines, including concrete towers.
The lightning indication products cover both basic and advanced detection and analysis needs. More than 2000 turbine installations are currently active, all with an excellent operational track record, and many for more than 20 years.